Slidable latching seal assembly



Nov. 5, 1963 J. R. BAKER SLIDABLE LAIV'CHING SEAL ASSEMBLY Filed Jan.17; 1961 INVENTOR (fa/10v J9 BAA/1? Arraemzrs.

United States Patent 3,109,490 SLIDABLE LATCHING SEAL ASSEMBLY John R.Baker, Mexico City, Mexico, assignor .150 Baker Oil Tools, Inc, LosAugeles, Caliltl, a corporation of California Filed Jan. 17, 1961, Ser.No. 83,187 17 Claims. (Cl. 166-114) The present invention relates tosubsurface well bore apparatus, and more particularly to the obtainingand maintaining of a proper seal relationship between a tubular memberdisposed in the well bore and a companion well packer, or other barrierdevice in the well bore.

Tubing is disposed in a well bore in sealing relation to a well packerfor the purpose of conducting fluids through the tubing and packerwithout such fluids leaking between them. Heretofore, under some wellconditions, the tubing shrinks or elongates substantially due to thermalchanges, with the possibility of disrupting the sealing relation betweenthe tubing and the packer. The same adverse result might pertain uponsubjecting the tubing to high pressure, which tends to elevate thetubing in the packer and disrupt the sealing relationship therebetween.Elongation of the tubing due to temperature increase or its beingsubjected to upwardly directed hydraulic force can induce buckling ofthe tubing which might cause its failure.

An object of the present invention is to provide an improved sealassembly between tubing and a well packer, or other barrier in a wellbore, that permits the tubing to move longitudinally in the well packerover a relatively wide range without disrupting their sealing relation,and without requiring the use of an extended length of seals on thetubing.

Another object of the invention is to provide a seal assembly betweentubing and a well packer, or other barrier in a well bore, capable ofbeing run in the Well bore on the tubing and coupled to the packet, thetubing being movable longitudinally of the packer over an extendedlength without disrupting its sealing relation to the packer.

An additional object of the invention is toprovide a seal assemblybetween tubing and a well packer, or other barrier in a well bore, thatis run in the well bore on the tubing and coupled to the packer andreleasable therefrom without requiring the tubing to be rotated, thetubing being movable longitudinally of the packer through a substantialdistance without disrupting its sealing relation to the packer.

A further object of the invention is to provide a seal assembly betweentubing and a well packer, or other barrier in a well bore, that is runin a well bore on the tubing and coupled to the packer, the effect ofhydraulic force on the tubing tending to elevate it in the packer beingreduced considerably.

Yet another object of the invention is to provide a seal assemblybetween tubing and a well packer, or other barrier in a well bore,adapted to be releasably locked to the well packer so that it cannot bemoved in either direction by hydraulic pressure.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of a formin which it may be embodied. This form is shown in the drawingsaccompanying and forming part of the present specification. It will nowbe described in detail, for the purpose of illustrating the generalprinciples of the invention; but it is to be understood that suchdetailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a combined side elevational view and longitudinal sectionthrough a tubing and seal assembly, to

be used in conjunction with a well packer or other barrier in a wellbore;

FIG. 2 is a diagrammatic view in longitudinal section of the assemblydisclosed in FIG. 1 being inserted within a well packer;

FIG. 3 is a view similar to FIG. 2 disclosing the seal device fullyassembled within the well packer.

The invention is illustrated in the drawings with specific reference toa well packer A anchored in packed-off condition in a string of wellcasing B disposed in a well bore. The Well packer is discloseddiagrammatically in the drawings, since it is of any known type. Forexample, it may comprise the specific construction illustrated in U.S.Patent 2,507,262 or U.S. Patent 2,683,492. The bodies of the well packerdisclosed in such patents have a central passage 19 therethrough ofcylindrical shape, there being a lower shoulder 11 on the body 13inclined in a downward and outward direction, and also an upper shoulder12 against which a companion member can bear.

A tubular string C, which is usually tubing, is lowered in the Wellcasing to the location of the Well packer A and is adapted to beinserted in its central bore or passage 10 in sealing relation to thebody of the packer. This tubing string may extend to the top of the wellbore, or may be suitably connected to an upper device, such as anotherpacker (not shown), lowered in the well bore and set in the casing at aparticular location above the packer A, as desired. The tubing string Cincludes a tubular inner body member 14 having an upper head 15, andwhich may be of an extended length. This tubular inner body member 14 isthreadedly attached to an adjacent tubing section 16 thereabove, withits lower threaded pin 17 threadedly attached to a threaded box portion18 on a lower sub 19, which may have a lower threaded pin 20 forattachment to a tail pipe D, or other tubular extension of the innerbody member 14. l The periphery of the inner body member 14 is smoothand has a diameter substantially less than the inside diameter of thepassage .10 through the well packer A, or other barrier disposed in thewell bore, The inner tubular member 14 is to be placed in leak-proofrelation to the body 13 of the packer by means of a seal assembly 21mounted on the inner body member, and which. is adapted to be releasablycoupled to the well packer A, or other barrier, anchored in the wellcasing B. As shown, the seal assembly includes an outer tubular bodymember 22 slida-ble on the inner tubular body member 14 and consistingof a plurality of sections. Thus, the outer body member includes anupper section 23 having an upper head portion 24 adapted to engage theupwardly facing shoulder 12 of the packer body 13. Provided in thisupper portion is an internal groove 25 containing a pliant, elastic sealring 26 adapted to slidably seal against the periphery 27 of the innertubular member 1-4. The lower end of the upper section 23 is threadedlysecured to an intermediate body section 28, there. being a groove 29formed between these sections in which a suitable side seal device .30is mounted adapted to seal against the inner wall 10 of the packer body13. The lower end of the intermediate section is threadedly attached toa lower section 31, there being a peripheral groove 32 formed betweenthese sections in which a packing or seal assembly 33 is mounted, alsofor sealing engagement with the wall 10 of the Well packer body. Theseals 30, 33 may be of any suitable type. As shown specifically in FIG.1 by way of example, they may consist of upwardly and downwardly facingchevron seals .34, 35 with metallic spacers 36 therebetween. The innerlips of the chevron seals are adapted to bear and seal against theperiphery of the body sections 23, 28 and the outer lips against theinner wall 10 of the packer body 13.

The lower section 31 of the outer body member 22 terminates in alatching, locking or coupling device, in the form of latch legs 37terminating in lower latch feet 38. The latch legs and feet are formedby providing circumferentially spaced longitudinal slots or cuts 39 inthe lower portion of the lower body section 31, the latch feet havinginwardly projecting portions 40 adapted to be received within aperipheral groove 41 in the lower portion of the inner body member 14above the bottom inner body sub 19. The upper side 42 ofrthis groove istapered in a downward and inward direction and is adapted to engagecompanion tapered surfaces 43 at the upper inner portions of the latchfeet 38. The latch feet extend outwardly from the groove 41 and areprovided with upwardly tacing shoulders 44 inclined in an upward andinward direction, and also downward and inwardly tapering or beveledouter surfaces 45 at their lower corners which are adapted to be engagedby the downwardly tapering end 46 or the threaded box .18.

When the latch feet 38 are disposed in the inner body groove 41, theyare adapted to pass through the well packer passage 10. When disposedlaterally out of the groove 41, in the manner described hereinbelow,they will extend outwardly to an eifect-ive diameter substantiallygreater than the internal diameter of the packer body passage 10 and arethen adapted to fit under the lower body shoulder 11 and be held inengagement therewith to prevent upward movement of the outer body member22 in the well packer A. 7

Initially, the outer body member 22 is held in a fixed position on theinner body member 1 4, and with the latch feet 38 disposed in the lowerinner body groove 41, by a releasable device in the form of a frangibleor shear ring 47 mounted in a groove '48 in the inner body member andheld within an opposed groove 49 formed between the lower endof theintermediate outer body section 28 and the lower body section 31. Withthe parts in this initial position, the tubing string C is loweredthrough the fluid in the well casing toward the well packer A, which haspreviously been anchored in packed-01f condition in the well casing. Theentire assembly can pass into the well packer body 13 (FIG. 2), thelatch feet 38 being disposed in the inner body groove 41, until theentire outer body member 22 is extending within the well packerwith thelatch feet 38 disposed below the lower packer body shoulder .11. Suchposition of the latch feet is insured and is definitely determined byvirtue of the engagement of the outer body member head 24 with the upperpacker body shoulder v12, which will preclude further downward movementof the outer body member 22 within the well packer A. During entry ofthe assembly 'in the well packer, the seal ring members 30, 33 areforced into the packer body passage 10 and will make a fluid tight sealwith the inner wall of the packer body 13, preventing leakage of fluidbetween the outer body member 22 and the packer body 13 in bothlongitudinal directions.

Suitable downweight is now imposed on the tubing string C. Since theouter body member 22 cannot move downwardly, the shear ring 47 isdisrupted (for example, a force of approximately 3,000 pounds may berequired to disrupt the shear ring), which then permits the inner bodymember. 14 to be lowered within the outer body member 122, the latchfeet 38 being cammed outwardly by the tapered side 4210f the body grooveand disposed outwardly under the lower latch shoulder 11 on the packerbody 13;. The tubing string C and the inner body member 14 attachedthereto may then be lowered, the per-iphery 27 of the body then beingdisposed behind the latchteet 38 to prevent their retraction tfromlatching engagemen-t under the lower packer body shoulder 11 (FIG.

3). The tubing string C and inner body member 14 forming a part thereofcan now be lowered to the required extent, limited by engagement of theupper tubing sub or head 15 with the upper end of the packer body v13.I! desired, weight can be imposed downwardly on the tubing string C onthe packer A, or the tubing C can be held in a freely suspendedcondition with the top sub 15 disposed to any desired distance above thetop of the packer, so long as the groove '41 at the bottom of the innerbody member 14 is below the latched feet or. fingers 38 of the latchdevice.

The inner body member '14 with its smooth or slick periphery 27 may beof any desired length between its groove 41 and its top sub 1*5,'whichis preferably considerably greater than the length of the outer bodymember 22 and its latching or locking portion. The inner seal 26prevents leakage of fluid in both longitudinal directions between theinner body member 14 and the outer body member 22, and such seal ismaintained regardless of the longitudinal position of theinner bodymember within the outer body member. In the event that the tubing wereto shrink or elongate, due to a substantial thermal change, the innerseal 26 would still be maintained against the smooth periphery 27 oftheinner body member 1 4. The shrinkage can be of considerable extentand the apparatus would still remain assembled with respect to the wellpacker A, so long as the lower groove 41 does not become disposedopposite the latch feet or fingers 38. Elongation of the tubing C canoccur as the result of temperature change, the seal relationship beingundisturbed and maintained to the extent at which the top sub .15 mayengage the upper end of the packer body 13. Even where such engagementdoes occur, the seal relationship is still retained, since furtherelongation results in the imposition of additional downweight on thewell packer A, which is anchored in the well casing B.

In the event that substantial hydraulic pressure exists below the Wellpacker, it acts in an upward direction over the outer body member 22 andtends to shift it upwardly of the packer body 13. This action, however,cannot occur since the latch feet 38 are maintained under the packerbody shoulder 11. Similarly, if hydraulic pressure above the apparatustends to shift the outer body member 22 downwardly, such action isresisted and prevented by engagement of the upper head 24 with the upper shoulder 12 of the pack-er body '13. Thus, the outer body member 22is locked within and to the well packer A against removal from itspassage 10.

In the event that hydraulic pressure is present below the apparatus, ittends to elevate the inner body member 14 with rsepect to the outer bodymember 22. The tubing C can move to a substantial extent under theinfluence of the elevating force of the hydraulic pressure, the innerseal 26 still maintaining its leakproof engagement against the periphery27 of the inner body member. The force 7 available for lifting action onthe inner tubing member 14 and on the tubing string C connectedthereto'is re duced substantially compared to the prior device.Ordinarily, the end area over which such hydraulic lifting force can actis the area between the inside diameter of the inner body member 14 andthe inside diameter of the well packer body 13. In the present case, theend area is much less than the area just referred to since the pressurecan act only over an area of the inner body member 14 which extendsbetween its inner diameter and its outer diameter 27 engaged by theupper inner seal 26. It is evident from a comparison between the twoareas that the last-mentioned area is considerably less than the firstmentioned area. In fact, in a typical device, it is about one-half thatarea.

When it is desired to release theseal assembly 21 and remove it from theWell packer, it is only necessary to elevate the tubing string C, whichwill raise the inner gages the beveled lower ends 45 of the latch feetto hold them in the groove 4-1, causing continued upward movement of thetubing string C and inner body member 14 to move the outer body member22 upwardly with it, the assembly 21 moving up through the packer body13 and to a position above the upper end of the latter, whereupon theentire apparatus can be removed from the well bore, if desired.

It is, accordingly, evident that the seal assembly 21 is placed inproper sealing relation to the well packer, or other correspondingbarrier device in the well casing, without rotation of any parts beingrequired. This is also true of the removal of the apparatus from thewell packer, which occurs, as described above, merely by elevating thetubing string C in the well bore, and without rotating it.

It is to be noted that the latching mechanism 37, 38 is located belowthe seals 30, 33, which precludes the latches from becoming fouled bysand or mud weighting material that might settle out of the fluid on topof the packer. The inner body member 14 is always free to move upwardlywithin the outer body member 22 until its groove 4 1 is opposite thelatch feet 38, whereupon the latter move inwardly from engagement withthe lower packer shoulder 11.

I claim:

1. In combination: a well packer adapted to be set in packed-elfcondition in a well bore and having a passage therethrough; an innertubular member movable into said passage; an outer tubular membermovable relatively longitudinally on said inner member and movable intosaid passage; seal means between said outer member and well packer toprevent leakage of fluid therebetween; and a seal on said outer memberslidably sealing with the exterior of said inner member to preventleakage of fluid therebetween while allowing longitudinal movement ofsaid inner member in said outer member.

2. In combination: a well packer adapted to be set in packedoflcondition in a well bore and having a passage therethrough; an innertubular member movable into said passage; an outer tubular membermovable relatively longitudinally on said inner member and movable intosaid passage; seal means between said outer member and well packer toprevent leakage of fluid therebetween; a seal on said outer memberslidably sealing with the exterior of said inner member to preventleakage of fluid therebetween while allowing longitudinal movement ofsaid inner member in said outer member; and means for securing saidouter member to said well packer in its sealed relation thereto.

3. In combination: a well packer adapted to be set in packed-offcondition in a well bore and having a passage therethrough; an innertubular member movable into said passage; an outer tubular membermovable relatively longitudinally on said inner member and movable intosaid passage; seal means between said outer member and well packer toprevent leakage of fluid therebetween; a seal on said outer memberslidably sealing with the exterior of said inner member to preventleakage of fluid therebetween while allowing longitudinal movement ofsaid inner member in said outer member; and coengaging means on saidinner and outer members enabling said inner member to move said outermember in said passage.

4. In combination: a well packer adapted to be set in packed-offcondition in a well bore and having a passage therethrough; an innertubular member movable into said passage; an outer tubular membermovable relatively longitudinally on said inner member and movable intosaid passage; seal means between said outer member and well packer toprevent leakage of fluid therebetween; a seal on said outer memberslidably sealing with the exterior of said inner member to preventleakage of fluid therebetween while allowing longitudinal movement ofsaid inner member in said outer member; coengaging means on said innerand outer members enabling said inner member to move said outer memberin said passage; and means for securing said outer member to said wellpacker in its sealed relation thereto.

5. In combination: a barrier adapted to be disposed in a Well bore andhaving a passage therethrough; an inner tubular member movable into saidpassage; an outer tubular member movable relatively longitudinally onsaid inner member and movable into said passage; seal means between saidouter member and barrier to prevent leakage of fluid therebetween; and aseal on said outer member slidably sealing with the "exterior of saidinner member to prevent fluid leakage therebetween while allowinglongitudinal movement of said inner member in said outer member.

6. In combination: a barrier adapted to be disposed in a well bore andhaving a passage therethrough; an inner tubular member movable into saidpassage; an outer tubular member movable relatively longitudinally onsaid inner member and movable into said passage; a seal on said outermember disposed in said passage and sealing against said barrier toprevent fluid leakage between said outer member and barrier; and a sealon said outer member slidably sealing with the exterior of said innermember to prevent fluid leakage therebetween while allowing longitudinalmovement of said inner member in said outer member.

7. In combination: a barrier adapted to be disposed in a well bore andhaving a passage therethrough; an inner tubular member movable into saidpassage; an outer tubular member movable relatively longitudinally onsaid inner member and movable into said passage; a seal on said outermember disposed in said passage and sealing against said barrier toprevent fluid leakage between said outer member and barrier; a seal onsaid outer member slidably sealing with the exterior of said innermember to prevent fluid leakage therebetween while allowing longitudinalmovement of said inner member in said outer member; and means on saidouter member releasably engaging said barrier to secure said outermember to said barrier.

8. In combination: a barrier adapted to be disposed in a well bore andhaving a passage therethrough; an inner tubular member movable into saidpassage; an outer tubular member movable relatively longitudinally onsaid inner member and movable into said passage; a seal on said outermember disposed in said passage and sealing against said barrier toprevent fluid leakage between said outer member and barrier; a seal onsaid outer member slidably sealing with the exterior of said innermember to prevent fluid leakage therebetween while allowing longitudinalmovement of said inner member in said outer member; means on said outermember releasably engaging said barrier to secure said outer member tosaid barrier; and means on said inner member engaging said securingmeans to prevent release of said securing means from said barrier,

9. In combination: a barrier adapted to be disposed in a well bore andhaving a passage therethrough; an inner tubular member movable into saidpassage; an outer tubular member movable relatively longitudinally onsaid inner member and movable into said passage; a seal on said outermember disposed in said passage and sealing against said barrier toprevent fluid leakage between said outer member and barrier; a seal onsaid outer member slidably sealing with the exterior of said innermember to prevent fluid leakage therebetween while allowing longitudinalmovement of said inner member in said outer member; means on said outermember engageable with said barrier to limit downward movement of saidouter member in said barrier; and releasable means on said outer memberreleasably engaging said barrier to prevent upward movement of saidouter member from said barrier.

10. In combination: a barrier adapted to be disposed in a well bore andhaving a passage therethrough; an inner tubular member movable into saidpassage; an outer tubular member movable relatively longitudinally onsaid inner member and movable into said passage; a seal on said outermember disposed in said passage and sealing against said barrier toprevent fluid leakage between said outer member and barrier; a seal onsaid outer member slidably sealing with the exterior of said innermember to prevent fluid leakage therebetween while allowing longitudinalmovement of said inner member in said outer member; means on said outermember engageable with said barrier to limit downward movement of saidouter member in said barrier; releasable means on said outer memberreleasably engaging said barrier to prevent upward movement or" saidouter member from said barrier; and means on said inner member engagingsaid releasable means to prevent its release from said barrier.

11. In combination: a barrier adapted to be disposed in a well bore andhaving a passage therethrough; an inner tubular member movable into saidpassage; an outer tubular member movable relatively longitudinally onsaid inner member and movable into said passage; a seal on said outermember disposed in said passage and sealing against said barrier toprevent fluid leakage between said outer member and barrier; a seal onsaid outer member slidably sealing with the exterior of said innermember to prevent fluid leakage therebetween while allowing longitudinalmovement of said inner member in said outer member; means on said outermember engageable with said barrier to limit downward movement of saidouter member in said barrier; laterally movable latch means on saidouter member releasably coupled to said barrier to prevent upwardmovement of said outer member irom said barrier; said inner memberhaving a groove adapted to receive said latch means to permit inwardmovement of said latch means and its uncoupling from said barrier; saidinner member having means above said groove engageable with said latchmeans to hold said latch means laterally outwardly coupled to saidbarrier.

12. In combination: a barrier adapted to be disposed in a Well bore andhaving a passage therethrough; an inner tubular member movable into saidpassage; an outer tubular member movable relatively longitudinally onsaid inner member and movable into said passage; a seal on said 7 outermember disposed in said passage and sealing against said barrier toprevent fluid leakage between said outer member and barrier; a seal onsaid outer member slidably sealing with the exterior of said innermember to prevent fluid leakage therebetween while allowing longitudinalmovement of said inner member in said outer member; means on said outermember engageable with said barrier to limit downward movement of saidouter member in said barrier; laterally movable latch means on saidouter member releasably coupled to said barrier to prevent up wardmovement of said outer member from said barrier; said inner memberhaving a groove adapted to receive said latch means to permit inwardmovement of said latch means and its uncoupling from said barrier; saidinner member having means above said groove engageable with said latchmeans to hold said latch means laterally outwardly coupled to saidbarrier; and means releasably securing said inner and outer memberstogether with said latch means in said groove.

13. In combination: a barrier adapted to be disposed in a well bore andhaving a passage therethrough', said barrier having an upper shoulderand a lower shoulder; an inner tubular member movable into said passage;anouter tubular member movable relatively longitudinally on said innermember and movable 'into said passage;a seal on said outer memberdisposed'in said passage and sealing against said barrier to preventfluid leakage between said outer member and barrier; a seal on saidouter member slidably sealing with the exterior of said inner member toprevent fluid leakage therebetween while allowing longitudinal movementof said.

inner member in said outer member; means on said outer member engageablewith said upper shoulder to limit downward movement of said outer memberin said barrier; laterally movable latch means on said outer memberengageable with said lower shoulder to prevent upward movement of saidouter member from said barrier; said inner member having a grooveadapted to receive said latch means to permit inward movement of saidlatch means from engagement with said lower shoulder; said inner memberhaving means above said groove engageable with said latch means to holdsaid latch means laterally outwardly below said lower shoulder forengagement therewith.

14. In a seal assembly adapted to be placed in a passage in a barrierdisposed in a well bore and in sealing relation therewith: an innertubular member movable into the passage; an outer tubular member movablerelatively longitudinally on said inner member and movable into thepassage; a seal on said outer member for sealing against the barrier;and a seal on said outer member slidably sealing with the exterior ofsaid inner member to prevent fluid leakage therebetween while allowinglongitudinal movement of said inner member in said outer member.

15. In a seal assembly, adapted to be placed in a passage in a barrierdisposed in a well bore and in sealing relation therewith: an innertubular member movable into the passage; an outer tubular member movablerelatively longitudinally on said inner member and movable into thepassage; a seal on said outer member for sealing against the barrier; aseal on said outer member slidably sealing with the exterior of saidinner member to prevent fluid leakage therebetween while allowinglongitudinal movement of said inner member in said outer member; meanson said outer member engageable with the barrier to limit downwardmovement of the outer member in the barrier; and releasable means onsaid outer member releasably engageable with the barrier to I passage ina barrier disposed in a well bore and in sealprevent upward movement ofthe outer member from the barrier;

16. In a seal assembly adapted to be placed in a passage in a barrierdisposed in a well bore and in seal ing relation therewith: an innertubular member movable into the passage; an outer tubular member movablerelatively longitudinally on said inner member and movable into thepassage; a seal on said outer member for sealing against the barrier; aseal on said outer member slidably sealing with the exterior of saidinner member to prevent fluid leakage therebetween while allowing 3longitudinal movement of said inner member in said outer member; meanson said outer member engageable with the barrier to limit downwardmovement of the outer member in the barrier; laterally movable latchmeans on said outer member adapted to be releasably coupled to thebarrier to prevent upward movement of the outer member from the barrier;said inner member having a groove adapted to receive said latch means toprevent its inward lateral movement and uncoupling from the barrier;said inner member having means above said groove engeable with saidlatch means to hold said latch means laterally outwardly and coupled tothe barrier.

17. In a seal assembly adapted to be placed in a ing relation therewith:an inner tubular member movable into the passage; an outer tubularmember movable relatively longitudinally on said inner member andmovable into the passage; a seal on said outer member for sealingagainst the barrier; a seal on said outer member slidably sealing withthe exterior of said inner member vto prevent fluid leakage therebetweenwhile allowing longitudinal movement of said inner member in said outermember; means on said outer member engageable with the barrier to limitdownward movement of the outer member in the barrier; laterally movableatch means on said outer member adapted to be releasably coupled to thebarrier to prevent upward movement of the outer member from the barrier;said inner member having a groove adapted to receive said latch means toprevent its inward lateral movement and un- 9 10 coupling from thebarrier; said inner member having References Cited in the file of thispatent means above said groove engageable with said latch means to holdsaid latch means laterally outwardly and UNITED STATES PATENTS coupledto the barrier; and means releasably securing said U inner and outermembers together with said latch means 5 fi g g in said groove. g or

1. IN COMBINATION: A WELL PACKER ADAPTED TO BE SET IN PACKED-OFFCONDITION IN A WELL BORE AND HAVING A PASSAGE THERETHROUGH; AN INNERTUBULAR MEMBER MOVABLE INTO SAID PASSAGE; AN OUTER TUBULAR MEMBERMOVABLE RELATIVELY LONGITUDINALLY ON SAID INNER MEMBER AND MOVABLE INTOSAID PASSAGE; SEAL MEANS BETWEEN SAID OUTER MEMBER AND WELL PACKER TOPREVENT LEAKAGE OF FLUID THEREBETWEEN; AND A SEAL ON SAID OUTER MEMBERSLIDABLY SEALING WITH THE EXTERIOR OF SAID INNER MEMBER TO PREVENTLEAKAGE OF FLUID THEREBETWEEN WHILE ALLOWING LONGITUDINAL MOVEMENT OFSAID INNER MEMBER IN SAID OUTER MEMBER.